Laser induced fluorescence technologies applied for the standoff detection of bioaerosols

Abstract

Standoff detection of hazardous bacteria is important for instant countermeasures which prevent further spread of pathogens. Laser induced fluorescence (LIF) technology is a suitable method for detection and localization of bacterial aerosol clouds from longer distances. LIF allows for the standoff differentiation of bacteria from other substances in the environment like pollen, fog, chemicals or smoke. This standoff technology promises excellent capabilities for a security concept: After localization of the aerosol source, samples of bacteria can be collected quickly and subsequently analyzed in a laboratory by other methods like DNA sequencing or polymerase chain reaction assays for identification. A LIF detection system for bioaerosol detection which provides laser pulses with wavelengths of 266 nm and 355 nm for excitations is evaluated on aerosols. The setup enables fast data acquisition and provides a complete dataset in less than a few seconds at repetition rates of 100 Hz. Detection of different test aerosols from distances longer than 20 m is shown. Aerosols in different concentrations and compositions are generated and fluorescence intensities for different laser energies applied for excitation are discussed. The discrimination of bacterial aerosols from other substances is shown.